The invention relates to a method of recording at least one information signal on a record carrier having a recording track which comprises a preformed track wobble and position information indicative of predefined locations for recording information and a first one of said locations comprising an earlier recorded information signal, said method comprising generating a modulated signal representing the at least one information signal, and scanning the recording track and recording the modulated signal after and adjacent to the first recorded information signal at a recording clock speed.
The invention further relates to a device for recording at least one information signal on a record carrier having a recording track which comprises preformed track wobble and position information indicative of predefined locations for recording information signals and a first one of said locations comprising an earlier recorded information signal, said device comprising modulator means for generating a modulated signal representing the at least one information signal, and recording means for scanning the recording track and recording the modulated signal after and adjacent to the first recorded information signal at a recording clock speed.
A method and apparatus for successively recording information units on a record carrier is known from U.S. Pat. No. 5,187,699 (PHQ88002). The information from the unit is modulated to a modulated signal and recorded in the track at predefined locations indicated by prerecorded track position information. The process of consecutively recording signals in adjacent areas in a track on the record carrier is called linking. In the known linking method, after a first modulated signal is completely recorded, the recording process is continued up to a link position after the last data byte of the information unit. When a next information signal is to be recorded, the recording process is started at the link position by recording dummy information up to the start of a following predefined location. As a result so called linking blocks are created between the first recorded signal and the second recorded signal, which linking blocks include said link position. Device for scanning optical record carrier. Known systems for recordable discs are the compact disc recordable or rewritable (CD-R(W)). To obtain a correct position for a recording on a CD-R(W) disk, 2 parameters need controlling: the start and stop position of the recording on the disk, and the speed of the bit stream relative to the linear velocity of the empty track on the disk. Between sessions, the positional accuracy is controlled in a quite coarse way, based on the position ATIP information encoded in the pre-groove. Linking zones with dummy data exist between recordings to make sure that a play-back system has enough time to re-lock PLL""s and sync interpolation flywheels before reaching the actual user data. The data stream to the recorder should not be interrupted. If we want to cope with an interrupted data stream to the recorder, we should be able to stop the recording, and link the remainder of the recording without any loss of data, and also without any addition of dummy data between the 2 parts, since the latter would not be Orange book compliant. The biggest problem that today""s disk writers suffer from is so-called xe2x80x98buffer under-runxe2x80x99. When recording on a CD-R disk, the consequence for the user might be that he has to throw away the disk and start all over.
It is an object of the invention to provide seamless linking between recordings.
For this purpose, the method as described in the opening paragraph is characterized in that the method comprises reading the earlier recorded information signal and starting recording the modulated signal at a location dependent on the location of an end part of said earlier recorded information signal, while locking said recording clock speed to the track wobble. The device as described in the opening paragraph is characterized in that the device comprises retrieving means for reading the earlier recorded information signal and starting recording the modulated signal at a location dependent on the location of an end part of said earlier recorded information signal, and frequency locking means for locking said recording clock speed to the track wobble.
The invention is based on the following recognition. To be allowed to do interruption of a recording, the stop and re-start position should not differ by more then 2 channel bits. This to have good play-back without any loss of data for the user. This can be done by defining the stop position not based on ATIP, but based on the data itself, and accurate to 1 channel bit exactly. The start position is then controlled by reading back the previously written data, of which we know the end position, and determining the start position based on timing information retrieved from the decoder""s digital bit recovery PLL, flywheeled frame syncs and sub-code information. This guarantees the spatial accuracy of start position relative to the stop position. To guarantee continuity of the bit frequency, both parts of the recording are done with a clock locked onto the pre-groove wobble carrier. Both parts have then a bit rate derived from the same reference.